1. Field of the Invention:
The present invention relates to an improvement of a compressor control unit for an automobile air conditioner, having a compressor which is used for compressing a refrigerant.
2. Description of the Prior Art:
In an automobile air conditioner, a compressor thereof is driven by an automobile engine. Consequently, an additional load is applied to the engine by the compressor to cause poor driving characteristics.
In an attempt to overcome the above problem, it has been proposed that the driving of the compressor be controlled, for example, such a control is performed by a control unit disclosed in Japanese Laid-open application No. 195884/1982; such a control unit is provided with an acceleration detector which detects an acceleration of the automobile and to stop the driving of the compressor or to reduce an amount of the discharge of the compressor by 50% so as to improve the driving performance.
Furthermore, for accomplishing the same purpose as noted above, in Japanese Utility Model Publication No. 54411/1982, proposes the provision of an economizer switch for enabling a driver to select an ordinary driving mode or an economical driving mode so that, when he selects the economical driving mode, a temperature limit above which the compressor is actuated is set for a high level so as to decrease the operating ratio of the compressor whereby an energy saving is attempted.
However, in one of the former cases where the driving of the compressor is stopped, since the driving of the compressor is stopped at a time when the automobile is being accelerated even if cooling of the passenger compartment is required, it is not possible to obtain a suitable cooling condition whereby a cooling feeling is impaired. This is a defect inherent in one of the former cases.
In the other of the former cases where the discharge of the compressor is reduced by 50%, since the driving of the compressor is continued when the cooling of the passenger compartment is required, the defect inherent in one of the former cases is eliminated. However, in this the other case, since the driving of the compressor is still continued even when the cooling of the passenger compartment is not necessarily required, it is not possible to increase the acceleration capability of the automobile sufficiently. This is a defect inherent in the other of the former cases.
In the latter case, since the temperature limit is merely set for a high or a low level by means of the economizer switch, the driving of the compressor is continued even when the automobile is accelerated so as to impair the acceleration capability of the automobile. This is a defect inherent in the latter case.